It’s rare for an advertising battle to result in a lawsuit at all, much less come to court. However, a number of aggressive, comparative advertising campaigns launched in the heat of the recession resulted in a string of lawsuits. Gatorade and Powerade also wound up in court, following a disagreement over how many electrolytes constitute a "complete sports drink."

Experts say that the rarity of this legal battle means the outcome of the battle of hot dogs is unlikely to shake up the ad industry, or impact consumers at all.

"For whoever wins, it’s not really going to affect sales," said Michael McSunas, an advertising lawyer with Chattanooga, Tenn.-based Chambliss Bahner. "They’ll move on to another ad campaign anyway. And how many of us were even aware that Oscar Mayer even ran those ads?"

But for Kraft and Sara Lee, the result may impact future marketing strategy, and no punches were pulled in opening remarks Monday.

Leighton was pointing to a Kraft ad that consumers preferred the Oscar Mayer Jumbo Beef Dogs over Ball Park. The company has complained Kraft’s selection of its premium hot dog for comparison to Ball Park’s baseline product was unfair, and the ad copy insinuated that consumers preferred the Oscar Mayer dog to any Ball Park product.

Ball Park is the nation’s best-selling hot dog.

Leighton argued that Sara Lee’s survey was limited and flawed, excluding blue-collar workers. He also pointed to an ad that Kraft ran, which he alleged implied in large type that one Oscar Mayer dog bested the taste of all Ball Park dogs. In small type, however, Leighton said there was a footnote indicating that Oscar Mayer’s franks were actually compared to "the leading beef franks" of its main rivals.

The allegedly misleading ads were distributed to major newspapers and stores across the United States, Leighton said.